Few controversies in policing are as fraught as the use of Terry stops—temporary detentions made by officers upon reasonable suspicion of criminal activity, often accompanied by protective pat-down searches known as “frisks.” Studies have shown that racial minorities are disproportionately targeted for Terry stops, raising concerns about profiling and discrimination. Yet many police agencies view Terry stops as a critical tool in their arsenal. A related concern is the use of traffic stops—even on probable cause—to conduct more intrusive searches.

Accurate data is key to identifying and remedying racial disparities in the use of traffic and Terry stops. For example, when a study of Vermont agencies’ stop data revealed that black and Hispanic drivers were three to four times more likely to be searched during traffic stops than white drivers, the Chief of the Burlington Police Department called the information “illuminating” and spoke about “address[ing] this vulnerability in the way we do police work.” Likewise, when a report found racial disparities in the use of Terry stops by the Baltimore County Police Department, the County Executive stated that he was “disturbed by the data,” and pledged to bring in experts to improve bias and cultural competency training.

Yet despite the importance of stop data collection, there are few established standards or best practices. Should data be collected for pedestrian stops, or only motorist stops? Must data be reported if the driver hasn’t been issued a ticket or summons? Do officers have to report when they ask for consent to conduct a search? From state to state, policies are in disaccord regarding these basic questions and many more.

And these differences are not merely academic—they have a real-world impact. A Vermont Public Radio report concluded, for example, that compliance with Vermont’s data collection statute—which lacks meaningful enforcement provisions—was “spotty in many cases, and nonexistent in others.” Likewise, weak public disclosure requirements in Maryland’s statute led an ACLU lawyer to characterize Maryland’s public stop data reports as “useless” and “something you would do almost if you were consciously trying to hide racial profiling.” The lack of standards and best practices for stop data collection has resulted in the implementation of many policies that—although representing a step forward—fail to provide policymakers and the public with the information they need to identify and eliminate racial profiling.

That’s why the Policing Project has teamed up with the California Department of Justice and the Center for Policing Equity to create a guidebook on best practices for collecting and analyzing stop data. Operating under a grant from the COPS office in the U.S. Department of Justice, we hope to motivate national standards on stop data collection, analysis and use. This year, Policing Project externs reviewed and summarized stop data collection statutes in twenty-two states in an effort to identify what areas of consensus have emerged and how policies can be improved. From this survey and other research, the Policing Project is working to prepare a draft guidebook which will be used in a pilot with five California law enforcement agencies: Oakland, Richmond, Stockton, Bay Area Rapid Transit (BART), and the California Highway Patrol. Based on the results of the pilot, we will prepare a guidebook for use nationwide.

We can improve the way police agencies use stops. But the first step is making sure policymakers and the community are empowered by having access to accurate and useful information. By implementing smart policies for the collection and analysis of stop data, states and municipalities across the country can identify and resolve problems of discriminatory use of police stops, improving trust between the community and the police and ultimately improving public safety.